Opposing ethanol self-administration behaviors are observed when comparing two strains of mice: C57BL/6J x NZB/B1NJ F1 hybrids (B6xNZB) avoid ethanol (avoiders) after experience with high concentrations of ethanol and C57BL/6J x FVB/NJ F1 hybrids (BGxFVB) do not (revelers). The overarching hypothesis of this application is that these hybrids differ in sensitivity to the aversive, but not rewarding or anxiolytic, properties of ethanol and differential levels of FosB and deltaFosB in specific cell types and brain regions reflects experience dependent differences in voluntary ethanol self-administration. Hybrid sensitivity to aversive, rewarding, and anxiolytic properties of ethanol will be determined by employing the following tests; conditioned taste aversion, conditioned place preference, modified two bottle choice, and elevated plus maze. To define neurocircuits engaged by ethanol avoidance and revelry, FosB and deltaFosB immunoreactivity will be measured in ethanol experienced hybrids. Neuronal cell types of FosB and deltaFosB expressing neurons will also be determined. Effects of strain, dose, and quantity of FosB/deltaFosB positive nuclei (per brain region and cell type) will be determined. These experiments will contribute to the understanding of alcohol use and abuse. [unreadable] [unreadable] [unreadable]